DESCRIPTION: The overall aim of this project is to provide mechanistic data that will aid in understanding the role of dioxin exposure in the development of endometriosis. This proposal is based on the finding that rhesus monkeys exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) had a higher incidence of endometriosis than unexposed monkeys with the severity of disease increasing with environmentally relevant doses of TCDD (5 or 25 ppt/day). The focus of this project is to study the expression of mechanistically-based biomarkers of dioxin exposure, effect, and/or susceptibility in this colony of rhesus monkeys and in an in vitro human endometrial explant culture model. These preliminary results will be used together with the monkey tissue data to develop a full mechanism-based proposal to study the direct or indirect effects of TCDD on human endometrium and the role of dioxin exposure in the development of endometriosis.